SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b07604c8ba026662fb879271f271849ec8de067e5373ebf98be63c65e319fc07' 
  AND token = 'ZBkudiQnmoqveunigeTqc9FA552ZgnylOMMCx1cjq8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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