SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c555f2af679155acb8601959eb79de07bf17e4667698e8709cc599f670f7f856' 
  AND token = 'aRd0ylVdm1hnQO1enK51MhVPMduvUDtmExxtnDB3+OM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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