SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ab09d3f4e5dabe22bfbeb9aa04072b7c633f335318654f210d39092940ffc8e' 
  AND token = '3FteHw6jaWDVBUKNTk8MDFhl+sdrAW8UER6UHrYyN9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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