SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '426bb6019f93d1aafccebe1180a0cec023a04303926ce620ab366de38bea3998' 
  AND token = 'gBHTH2n71YxdOABh/pgC2rn9ofkU4aULT4YtGQkeooM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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