SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f4506d72765faaf6178cca009b527fb0724171628803f7683b26286c1ecab7c' 
  AND token = '4AKdChn4nOLlmJahTcB0J3Km5praxjw8B4OHUHhWjP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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