SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df25fc597d98e7668a324a4b7a301aec6d5aa21f8994500aa95ed6422fa65629' 
  AND token = 'JMi1q5FuQAvhFMaGeHzpBJbmLBWvMrG9G/5MAKZ5miY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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