SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c62aa46670cd28fc8cc935ec332e68725cf6f3fa71b1187696e8708189ef54b5' 
  AND token = 'OBAxP8YpQinuq/4k715NaSZfWh+gjC5VBy22tdswElM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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