SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7777cdd16172d04bacb81f1755edc3fe38a6512c3bd106cfeaf3b642a151f41a' 
  AND token = 'oAfPP/oFUgthasrBIpkAq5QO77tiUj0NpVB1kmkjmZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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