SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80675f52b26c86ee0c15262c685c4d1b8ce71643a2dbdf1d655e4d2c910cc8ce' 
  AND token = '2kqLgADYrRPstJKxq0qQrmdrTZmPvp+oXOZ4UPUrtc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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