SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0b0291c31070f93ad010fcb1625f5522924ff5c92ec0485925cbf43c706288d' 
  AND token = '2iiV6V/BTvIT90Et8iPImxupUuEU/MRgw0Qqg2jobBY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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