SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a56a642b21c13e17979f76e2abda248759ca1dcc67b2f9cbd6c0fb0d0bbc5b05' 
  AND token = '3p1MoHsJMFMpVaGMiE58DXoOF2aIm9SXZzQtprpCHqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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