SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9fc0089195f4d2017a42228f76e47eeef19a779fa0cc5338e2697aafd2bf5c8' 
  AND token = 'LSmucyXh3usppCVAzoy1BlM1IHwiubrBEX9iU74fjUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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