SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce29ea0595058ebbbd62eb1e1a0f46d3424c6ef5c154c92e03afef961400826a' 
  AND token = '6kA/AKR9mjCW1pi+uIcb9ZVq7pGL0otvPlCOxzbcCGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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