SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b403e995abdef817faa1d7497198a0e695f6d71fa7f57861426e7cab569f0780' 
  AND token = '8EWIXxjyJm1TE4w7t46wXhfaCbcL6DsXxuXgg2J4yUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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