SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11d93f915dbb13ac5ea61d2d3f8552b191b41eba2ab660f4f7584d5686fa0f77' 
  AND token = 'A9hiw2/tzOh02nYElp1GZYTvX7rmwcG3ezKaq+Eh/dU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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