SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14cdc2d21a01b74bd29b586e704373c0b7c0a8af2453f675315128f526ce1e61' 
  AND token = 'iZwAKNgcF2ZbC0qmJE8OhD0/xEgn1kbUe94EIVaa0Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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