SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbe44e8d58c62e82ebfb2bc9557c31c785ebc71e49316a8ba3fef27113c6d16e' 
  AND token = 'O+m828YUgqRv5KqZNX5dF6fEaeenLGhd1ApIn5hg0r0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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