SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c94caab0e6d62c96fde8b40899aa7ee94967051d507529686dfd77df921efbe' 
  AND token = 'XLvH3xthpmuI1pQr+MvfCc5wesx/1EHHJw6CKG5MfwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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