SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9a15364f463b7dfd91ffd65dbcff7bb355802dd767bee713a910842e6e498e9' 
  AND token = '9WtqN3ZCSyEefgk2qssfLvWRNbgxeZgxxDMxMKxWHe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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