SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36a156727d60bcd855df9d8e343e69ad12c544dce32a0e0b20920ccbc1d1f966' 
  AND token = 'krKGdtGiQLePgkWsDvUrWusc9RFtjSllx2yfKacugVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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