SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91c8629dc76a57899a6f7308054b809aa04c796c07e26b4f7b7fba087d440884' 
  AND token = 'tZ7OCYwQGgsJHSYuATOd/8IkJSQlonjz5ITsqVw23iQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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