SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '794e505d18589ae3a7cbd336ad194b4baf20229ec5141d057fc28c273b4762db' 
  AND token = 'Di+IyQCnwPzfoQf8ZiEGl2KpM6C3mTPiYE0dyxOhqqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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