SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a86510aaf569ebfd5a420eec735f22db836282a3a9589bf73819d5a7c58f9d76' 
  AND token = 'WhuBuKarnkYNHHCshAoxeo6ujIBXrgmVTSE6iZbUCws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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