SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70481893691a288c985580c95ec56cb9ddfc5e1e0f266bcd2946c8c95499102f' 
  AND token = '69vcCta0/S7ALzPrhmJqVvJJPkNWeBGDMsRp8H0X6nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}