SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '363a53a2c059ba54129de39fa80f7682a5c9aad92cecb3d7342531dbedcf6825' 
  AND token = 'f/RKNQlyTj/lvmb3tDobM93958iD+35BeVI2EZApOoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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