SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ef4119324f7c392e30972cffffc480ae0488bbba807e0bf57c3bb1741947224' 
  AND token = '7sk1nCncmnj9NQJkGYw/5qPFl+UkZfEUqySU56PSDEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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