SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eac06eb397efd4107848fdabee647ff603768b06e08934e8a160fc872e1d710f' 
  AND token = 'NjRgnq0GJciNbmla9MZ0a73nGRHi92Lyzec8DK1PvwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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