SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77e7578de3c4e6fcd3716a415d83eabab58265d1b8a6b4ad54e8e1675da59df3' 
  AND token = 'Arkme/S7CoBiteaxkukUjDpw0tDKFtBzf7i7cE3c2Cc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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