SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdb5b8ccca7bf98f89769f2075bf8dfb458f142d1957f0ac53c5b351330117e2' 
  AND token = 'tudQp8QwBhMeqn/puwOgM3TgJ96nWpOgh+pzCxUqL4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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