SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '608001a98c2d7057192e501fb5270c81b2bbd3ca82c74ce113875232b1b43663' 
  AND token = 'iHByVNQNUjq1hIOkPFlFZrFdjSz+NVOgJmOtkafm95I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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