SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14444f382dbdae7782780aa10803c322600c59b8cf7349e91942211c96ecaeb3' 
  AND token = 'b/XoDNBY1/7a4UUWVSgBV1JSWOc0xLHfxG0XnKE+zOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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