SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '443b2251795b5c18cc5c2a62efaf0e51963d4d997ff721a351243b995308c4d0' 
  AND token = 'J0EbYgo185kegsFrtOkCxTDkxmopQNC79kL4eq7RmhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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