SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1472f1bb58ea6b6a05378ba2156cf78ff29714e6021a6d45c1937f33d03dec71' 
  AND token = 'Vevl8/h8rwhig4Lxr+Sq7TbjuaL5o0L92JG0n5AtQdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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