SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd4aecd69557953c48136822d9ca76190ac34bd88ca8afcf20a3fc659d14ee73' 
  AND token = 'yhOzUa7t1//SauYuDT5cOTnNwZuMzyd3WQvSgBIm/fI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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