SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ffcbeab5bacbf585508094cc173456c517532348ca336c0fe3c419c64d1f7ece' 
  AND token = 'A5CU9S7e9GN0eJ3yaVcV2T2vAlE3yqS8024gmsLtaNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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