SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c582abb5d1c7612e71cc6b8219aa0f0823670294519bacf02145cc54e42f98b0' 
  AND token = 'Xq3LgMB0S6TJVnfmhI/QgxhjlTZtgsdXHT8/FYl9YFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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