SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f68a3ba7e58f0787c3eb82b1b187f0830ceb05a063c6a09696aa3e5355191668' 
  AND token = 'rl37DWWvgW4nYpV8oLEZoK+l6AIeiSQKyv5+WLGySVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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