SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44219fb60efde27cc640866d549268c9209e75ea704ebeb1af095d007bd1b9ae' 
  AND token = '127ZLIcdo1kIwKE0otnjzkf0I1Acvsk299/EUFnRHqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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