SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a2e1fd1dd4bcedabe6aad082aa27359323eec298862ac600b3d09a94f57e3b3' 
  AND token = 'vHQ4COG4gqbfCZeB6dkxCiwbY6VpH8IlkqKC6KTj7rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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