SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe29de146bc057b295cc35b022a68e12fab022e136010ce2371872f1cfb5f7c5' 
  AND token = 'EPQfXs4FjtyopqDYecpWpovfI+LQSVXwGXmMinlGdHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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