SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d3c360215758fd1f3de234301d875f84206213208cc57aa60600aefe2e9e39' 
  AND token = 'K196MXhdZh0nzpl9Qv/0TELBxWd7kkzoCcjYLCVAVao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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