SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98b7197c0893ae3cb32602e9422c497a53f5e4b671bad4207dc36e129a5bcee2' 
  AND token = 'afVQ3iTdukjSJJpYtEKldtbBngBQZuxrnryhzFx8vPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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