SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a861b06d806b601fe4eeabf37fc355407509b5288a7d8e66b5650f12da1b5e' 
  AND token = '19R4PcylNn+o0oDNbioIOFYHorMZqQEiT21R5nw2XRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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