SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccf995a20cefcc86d4599a3b0902a5c6a481c36334608ec8ff392446b3e872c5' 
  AND token = '9Cf4jJyKPA0kHYViqQz8OwynWpvDw5zjB51Y6p+xS+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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