SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b97de83d4107ffa8514e3f15649f75f201c0dc5d4c3b801683a63a926135b0c9' 
  AND token = 'CzdFyH1WU7JOl7nuUzFRmEnC4/TInrlYGEgTR1bUbj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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