SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9be350fefcd40b20b0ca12f360216a121814aed19fe30b38449213d7a401c1ff' 
  AND token = 'Dldcc8TK93RY4ElltkhHybePWGF5+zXNQGWKAgf0uy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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