SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9eabbbbe8aad2b180caefb98abd7410e7e3a18520aade3cb07a4873ffcc7906' 
  AND token = 'lTuxVQNHmwz8Lzm/iefP+BXlb3DqgEXvcU9ROcax3TE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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