SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bf88736874cec7831e97ed5c9fc294b62d2365b56d3adebe0427bbd4a4a014f' 
  AND token = 'sAxu1QiCPBvYDjgGLF022OXGm8wKs8NiD6VUJ0OBXHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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