SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd7393f714a413fd553b0329ba8546b558f1821b009f28911cde1e47d0f09ed6' 
  AND token = 'yW8BDrMUh2bqYavJGKFZaw0ktdxN4GuVUL4dhez2JKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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