SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '922a07ec42dc2cc7a416df03f7a1eb86e787adf1126073be66a35bad6a90c903' 
  AND token = 'R/hj8ZBcQWCZSKNZV4EuVxTnJ0KgDJqoZr/JLIDXC80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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