SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5692d76d8eb715f3b6ca5fa5a9e12c415d456e7f0f10ca727d0774360f9027f8' 
  AND token = 'GICqfZ96/jM37E14VIzUKr/gLeqVFq33DyvzcmBHzkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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