SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e98e65eb0182e947bf991fda5ae65c74eaa95574e572453a2efd02c20685a12' 
  AND token = 'cYPX5vM9nSFKD77R4h4PVVxBJVUVVVYeXb6jJqMGmTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}