SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f59bbdfab218cf2f13a157e0820141b83197d33ecfc305d0598ecbdcfd30cd29' 
  AND token = '9pTNU7nfgCnuQokizO4GTtX3LBZgDazZHKSy/RKp/gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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