SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7238ae590b3b4270d681b351aaa746cb6f230ca11a319a3f8a71e6682b684b95' 
  AND token = 'dxv0Cv/VhY0l1uJwe8llRjfoN8MvtJxGUaJqvguYOys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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