SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0744bf3174b6ddece00569a42d571e0f161b38b39c83f19715e2938c7a257da' 
  AND token = 'nta93rLio9PN7+oDSXm1LSKuhQuoBzDCrQUjDBF2deQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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