SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c87f10cddcf824efa26cc338efbcc4d96c15afda46973aaa6101236f54eb67a' 
  AND token = 'kjn9zrCVbb+cPFtxks+K+OE0p0NRLJqcSYPCH6PugRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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