SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfb5dd636fce3f1c83abd45ecfe10abad159f93878437560db46f7d8d83bc9e3' 
  AND token = 'P2DKo3AQZTB8Y9UBhbbxkAfaEMh1u/1VVbpebHruvfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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