SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0482120d28f8f15bc82920a1710a13f5388c476baacfbb05784b964a91dfbcb6' 
  AND token = 'TCo2SOQ1PaR3DMOFrfX4QcEcYn6e68fmawn5Egq3yIQ=' 
  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"
    }
  }
}