SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '824d7b0d62a973de1ff2cc55385f62923dc6533fcaf6934c0c7f2a78af13ffee' 
  AND token = 'sCkjizzFkLy6WTmbDEcPHAhngDiFHg1LlfAQlNaxCPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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