SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ce5690fc1d8856e9ca4494f1a0f5050c59808ab3f90f29c4ca3987c400b7d0ee' 
  AND token = 'VbGXeZ3TNBD3FiUgzu9onoVpjZHIIi30xt8cWMS88zQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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