SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daafcdce63e68755ccd543d88497e377032e30506e44f875f413c9f84ebb80bb' 
  AND token = '6SQ9QdxtTHSLYEU0xGZEIdk/TZM9UxYndZrPjfCgoD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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