SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '826ab415b2489ab982ad18d78d34b75246faeaaa1b2c32e1387897454e81055d' 
  AND token = 'qTrM4dDB1YzKO+PfQCqTXYzoNTIFVcrrNdJS6iaxExY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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