SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '274a0454d8accb4b853ecaec7cff4a6e16d289fdf080a0f35a323770e20032c2' 
  AND token = 'ziOSybH6QKGpkAyUifP2DjCRiGhyyVECvAYXetIj1MU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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