SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9953405251fb3e07e172c05371d74c39f34d811f89d0cf4614e0887d8b7c6e4f' 
  AND token = '+OJqCn+WHXfIgHBCX1oMluXc0ulZnIw3YTsRXt6rzBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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