SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39e9db4ae8c6103c0a663fca405f6068ef08689d061f7c475405331e66908545' 
  AND token = 'V5i6DSaydrwVZ41R3+Y4phUTDuRxLmidYl0I9297Y8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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