SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da9f3d3ab1698adf27dbd6b7876cc39a5f032ef31e055f930dc9349a050a1590' 
  AND token = 'ht9cNbnSOzZU3OPlO/mPdKfy401XVxjazmn5dWsTMQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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