SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c73594706e377a4936715c03be350db4e1a313ced3b6418e8171f29a1ec25a' 
  AND token = 'e62l4KYtAPyGoQILLe8zVsRT3AtpB3DXEMiANrQDhJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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