SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ea4cdd9b53802ff103eef769dfcbbd3a15bcd94297f3ab9f959e08cabc082bf' 
  AND token = 'bbeIfVsDCapvEoYgLNqeTFWf5SoWXwlkX7gRB7ZihIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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