SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b2360c1c6478d0de02f1d484bf526613999303c6fcf43e972e60d45d855211a' 
  AND token = 'vJ2Px1fjYzO6XwXKYz+h7zKBRp64JHzqAICmJXMDRiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}