SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ed87b3154e0acb094000d53efeb8db93a88fece1175b1b1bff05cfd6233e116' 
  AND token = 'jj/sd6iwgMSFCMM3cLIn51mN2UCSk8txdbr94HbFLEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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