SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8eed952fab140790b28362be5bd510cf240df2eb4acdadccbff2b79ea61d729f' 
  AND token = 'nyQRD3nCv/TZk79WL/Kwe0KP1FufXldeLsuPxSfu8TA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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