SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c543b3e1b0750c4ab78cbead8d5d4f9e0871266db761d123bf5e6fcd2ac9dba' 
  AND token = 'GFKtr8upVIgXz8qKdOz8cRrMA6sDLPcTn3xpxPD2k+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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