SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '697d2a18e6a1768dd858905efe38946a6744eb3655b49da934ce2379153ecaf9' 
  AND token = 'zqzI4DvVDHppHhvc6vF+SYKh+ABjqJZ8g2m9rTo+Ecw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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