SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d09e927da427bf7c19f8dc149c62ddcb3c29231038ad45680e5849144e9e222' 
  AND token = 'dhoUd1h6ytVgWBQF8FYlDNcKLftPUpfE0dUDodGIqho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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