SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '667800277725297b8631065e6a4422a7ab7e79c30c49737cf838fbcbd59e14eb' 
  AND token = 'Pk91ubk7yUWSXbshseXpjZ0UqQQm5v+puYzwsmnn/E0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}