SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce4c66f9482169b482aea9c63e1b351028b2cac9b4bfba522c61a6f372f8d6f0' 
  AND token = 'PYoiY/UPnsr4f+7kILshiR4UsZ56rGJwomasMANLaL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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