SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf64641bca93051a3d9de8706186e41898909e44b090a66433ecc5cf69e2f5e9' 
  AND token = 'lgTfC7aS2yw7E2jiqb8JyBUJoJThCvsaWDTOj0SVnhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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