SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a49a3f97f3ad7eddef795451f59232989fb2d1de5809e6077027ad3c040ec115' 
  AND token = 'Dat0mEvLnNYy68UGBR/1An7otaQHUDdvYC2BXU1TCsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}