SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77cbf1f0abea3cdaef74440ace4cedf9d8654d52aa7e39bfddb3d7c7b8c5322c' 
  AND token = 'geG/egdkLY8bD9Oooodubb6fOwjmajVvVMDms6yU22Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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