SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eecaa663466df9324389e942e905ab6b58c73027c7c50cf406f974619f59df7c' 
  AND token = 'ERx3c2eqZVgKUtPZMTC1NGB5qGJtMwdt8+A92FZOfzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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