SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '669e053e3ba73c68de61347ce1452dd01573e29fac024342b0d50cea068a78dc' 
  AND token = 'UG8pIbWHIYueTpt0/cS39MeBmYTjUFheYNlwICLJnoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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