SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32c7db2e7160d4f8c2f521f764fd5525821e67c0326cddb802fa1d12825c90b' 
  AND token = 'XaKXTroZduvzVKKt+AKfFPHNv7jv7aiLH7nduJEHJbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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