SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '798bb87cff1260a452c14841ff75078baf5ed723187777ce371f275fed80b6fd' 
  AND token = 'yim4mOgFSJRITDa2MM+zgLKLJoQJTwvK7jqmamRdh+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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