SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3367fe42d14c30d0fee1712d813c1ba95bae0972fb48dee13d9898bd18e61fc0' 
  AND token = 'p4VwFra9lbzM8M8RoG9SVEFOvPXsAEp/FNTjPESWFDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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