SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24c7509e5e0ab16d5166a6f1890edd4eee1d0d2f0b430e5e12886bd139c37791' 
  AND token = 'c7WOyMnGOQIJPw6Co5tGoNFRixNP6VzkgPFO1XR6zxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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