SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a32c0c8bcaadb3498f3c0dd7e670a89a94758680c48f70cd0cdd19f5dc6fd874' 
  AND token = 'fAmddSVc7rrJgYQpSgmpDGMSAyg9iBHyKtXfuOMEQdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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