SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7267c7620ba6d129733f91254da8792d835295ac16076b06224381017e33602e' 
  AND token = '9G7FLQbTwfmnO1GlAhoGWBfZtfuCUwzluus+bzjGL+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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