SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aba35deff68fc7d022c3b894c5cf445abeda41d1f053f82911f3e169c7dc9a04' 
  AND token = '5094xpMFv4/7SMdUUD58sAYyiseRL55LO1wiU/yejAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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