SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e95e91f2577455c89daa392cc15881d416d55196d0720c467b650dbf001cf8b' 
  AND token = 'N5f0n5jFTHELS02GbVmkGyICSF7RUA6Qh9MjiLM4JhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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