SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cf0d8ab0b444f4b85d370f9d62754fdd98708f194179bed8847593fddf80b6c' 
  AND token = 'KEUMwbImiQvRanWpdVu4TqnnjS1Z3zxq4LMRePL5aWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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