SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9856e9f002e14523fc9c98ebcf06751ba5287f5973a9bfb814f2daa60cc4bf4e' 
  AND token = '0C5BQZ7X0ip8Kv1EkdPG+WPFGqDD2x/BzZ6WWm9vCSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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