SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80d070d633ef070b3b220c6fb4f149044b2b7db3c301793539d3cad4ac21e6af' 
  AND token = '5f/WBj86fbViRw1JIOoqrRGAzYL/TlVXZRSH5VhYngU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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