SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd483f036efb82b60c23cf99789f156e5e1a76e67bc6072600513099725577c0b' 
  AND token = 'vZI7hloyZYrUicMp1GSiw1js9GOOskMsjE0oYLeWP3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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