SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14c24d08643fd7bf6ed691fdd8e3483c1e2ced4393e597428627d350cb3e7ede' 
  AND token = '9m243Rrcqre5vmg+jzBzPUpF4k8/j27RcbrR7mHZTAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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