SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a8fd6bbb096d86cffc5d91317f95652d30cdff30252fbe70b48d6cc9975ec42' 
  AND token = 'xKyc+kDRig+sVVDp8tf78zOLqISpEZn9ABVYW0r8FzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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