SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b6c62eb07c1b0f526f61d8257c7fc739edc62aa493b90fbc5dff1d568da25b29' 
  AND token = 'R9H1zT5CLGboSew/eQ8yFpNvYFGCvQylTGGqFBQSeVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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