SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3dfea6f30b62ffb39d213c1bafec8706df2bcb6afc8ea32bb4455a1264a63b3' 
  AND token = 'saCRvpxuRPyKnsUR8IvWnDxVb8cmUoAl/tpfUnKACy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00179

JSON explain

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