SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e55914b5f55ed619000528511b5ece2b92d22b3275c5886c06bd7ed1da842f9b' 
  AND token = '0yX8ufqPyC0PwpAHioMZiGrJM4sxRurOISzVPQXEe3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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